中等电场下BNMT基无铅陶瓷介电温度稳定性和储能性能的提升

The ceramics (1 − x )Bi 0.58 Na 0.42 Ti 0.96 Mg 0.04 O 3+ δ - x SrTiO 3 (denoted as BNMT- x ST) were prepared via a conventional solid-state sintering method. Effect of SrTiO 3 content on crystallite structure, microstructure, dielectric, and energy storage properties was studied. The results of both Raman spectra and X-ray diffraction curves indicate that the introduction of Sr 2+ causes lattice distortion. Grain sizes of the ceramics decrease due to the doping of Sr 2+ . The breakdown strength increases higher than 120 kV/cm for the doped ceramics compared to the ceramic with x = 0 (89 kV/cm). BNMT-0.35ST exhibits excellent dielectric temperature stability between 46 and 289 °C, meeting the requirement of TCC ≤ ± 15%. The recoverable energy density and energy storage efficiency of BNMT-0.35ST are 2.9 J/cm 3 and 84.3% under the medium electric field of 265 kV/cm, respectively, which also exhibits excellent temperature stability between 25 and 125 °C as well as frequency stability between 5 and 500 Hz. The introduction of SrTiO 3 leads to the formation of polar nanoregions, enhancing relaxation behavior and improving energy storage properties.